N(17+x)=34x−r<br> you must solve for x

Divide 33 photos into 2 groups so the ratio is 4 to 7

lapo4ka [179]

First you'll need two equations ( you can use any variables you want)
A= photo group 1
B= photo group 2
First equation:
A + B = 33
This is because the total number of photos from both groups is 33
Second equation:
4A = 7B
This is because the ratio is 4:7 so for every four photos in group A there must be 7 photons in group B.
Then take the first equation A + B = 33 and subtract B from both sides. Making the equation A = 33 - B
Then with that equation, substitute it in for equation 2 and it will look like this. 4(33-B) = 7B
Then distribute the 4 to the 33 and the -B making the equation 132 - 4B = 7B
Then add 4B to each side
Making the equation 132 = 11B
Then to get B by itself you must divide each side by 11 making the equation 132/11 = B which simplifies to 12 = B
Then plug in 12 for B in the first equation like this A + 12 = 33
Then subtract 12 on each side of the equation to isolate A so A = 21

So
A = 21
B = 12

4 0

4 years ago

4(x+1.5)=38 solve for x

Kitty [74]

Answer:

x = 8

Step-by-step explanation:

4(x+1.5)=38

Distribute the 4

4x +6 = 38

Subtract 6 from each side

4x+6-6 = 38-6

4x = 32

Divide each side by 4

4x/4 = 32/4

x = 8

3 0

4 years ago

mariarad [96]

Answer:

$p_v =P(z>2.087) =0.0184$

So with the p value obtained and using the significance level given $\alpha=0.01$ we have $p_v>\alpha$ so we can conclude that we have enough evidence to FAIL to reject the null hypothesis, and we can said that at 1% of significance the mean for the control group it's not significantly higher than the mean of the treatment group by 1 point.

Step-by-step explanation:

When we have two independent samples from two normal distributions with equal variances we are assuming that

$\sigma^2_1 =\sigma^2_2 =\sigma^2$

$\sigma=2.5$

And the statistic is given by this formula:

$z=\frac{(\bar X_1 -\bar X_2)-(\mu_{1}-\mu_2)}{\sigma\sqrt{\frac{1}{n_1}}+\frac{1}{n_2}}$

Where z follows a normal standard distribution

The system of hypothesis on this case are:

Null hypothesis: $\mu_c \leq \mu_t+1$

Alternative hypothesis: $\mu_c >\mu_t+1$

Or equivalently:

Null hypothesis: $\mu_c - \mu_t \leq 1$

Alternative hypothesis: $\mu_c-\mu_t>1$

Our notation on this case :

$n_c =45$ represent the sample size for group control

$n_t =45$ represent the sample size for group treatment

$\bar X_c =5.2$ represent the sample mean for the group control

$\bar X_t =3.1$ represent the sample mean for the group treatment

And now we can calculate the statistic:

$z=\frac{(5.2-3.1)-(1)}{2.5\sqrt{\frac{1}{45}}+\frac{1}{45}}=2.087$

And now we can calculate the p value using the alternative hypothesis:

$p_v =P(z>2.087) =0.0184$

So with the p value obtained and using the significance level given $\alpha=0.01$ we have $p_v>\alpha$ so we can conclude that we have enough evidence to FAIL to reject the null hypothesis, and we can said that at 1% of significance the mean for the control group it's not significantly higher than the mean of the treatment group by 1 point.

5 0

4 years ago

HELPPP. i need help with this i have trouble with ordered pairs

Anton [14]

The second one i got (0,-2) first one i got (0,9)

8 0

3 years ago

What is -5+3

VladimirAG [237]

Answer:-2

Step-by-step explanation:

if you count from -5 and take away 3 it will give you -2

8 0

3 years ago

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N(17+x)=34x−r you must solve for x